The larval forms of three species of Diabrotica beetles, the Western corn rootworm (Diabrotica virgifera virgifera LeConte), the Northern corn rootworm (Diabrotica barberi Smith and Diabrotica barberi Lawrence), and the Southern corn rootworm (Diabrotica undecimpunctata howardi Barber), represent serious insect pests of corn in the Midwestern United States. Approximately 30 million acres (120,000 km2) of corn (out of 80 million grown) are infested with corn rootworms, the larvae of which can cause losses estimated by the United States Department of Agriculture on the order of about $1 billion per year.
There are many different management practices aimed at the control of corn rootworms, including corn variety selection, early planting, insecticides, crop rotation, and the use of transgenic corn varieties; however, none on its own has proven to effectively manage the pest. An additional complication exists in that corn rootworm insects have shown a remarkable ability to evolve resistance to several control measures, including insecticides, cultural practices, and resistance genes that have been introduced into plants.
Thus, there is a constant need for new mechanisms of corn rootworm resistance in maize that can be incorporated into an integrated pest management strategy.